In means of transportation such as motor vehicles, permanently installed navigation devices simply, quickly, and safely guide the driver of a means of transportation from the current location to a desired destination without the driver of the means of transportation first having to elaborately plan a route and obtain appropriate maps.
For this purpose, appropriate navigation data based on charts, maps, or street maps are available stored, for example, on CD-ROM (=Compact Disc-Read Only Memory) or on DVD (=Digital Versatile Disc). The navigation device uses GPS (=Global Positioning System), for example, in order to determine the current location and calculate the appropriate navigation instructions that lead to the predetermined destination. The navigation data, in this connection, preferably contains data on roads and paths for motor vehicles.
An important component of the above-mentioned basic function of a navigation device is the processing of the driving lanes on the roads, especially before, at, and after intersections. Driving lanes, in this case, are to be understood as the fanning out of the driving directions, in particular before an intersection, painted on the road.
The processing of such driving lanes, which may be found directly on the road surface or on signs installed above the roads such as in the form of sign bridges and/or electronic alternative-route indicators having directional symbols and/or distant destinations, will initially be required only at freeway interchanges, but later also at all other intersections having driving lanes.
In this context, it must be considered, however, that so far, in conventional navigation devices, the processing of linked consecutive driving lanes is still inadequate. The driver of the means of transportation is not provided with information by the navigation device enabling him to optimally navigate the means of transportation through street traffic, especially in the case of a rapid succession of multiple intersections or forks in the road.